Radiospeaker



A. A. KENT RADIO SPEAKER March 19, 1929.

Original Filed Oct. 30, 1925 2 Sheets-Sheet l ll /1 266,17?? BY am@ if, @am

l ATTORNEY.

A. A. KENT RADIO SPEAKER March 19, 192.9.

original Filed oci. so, 195 2 sheets-sheet INVENToR.

ML MM Q @f Y( QW @ATTORNEY Patented Mar. '19,,5 1929.l y

UNITED STATES lP.tiranti-r .ori-Ica ARTHUR A'rwarnn KENT, or nnnnonn, PENNSYLVANIA.

` nanrosrnaxnn.

' Application filed October 30, 1925., Serial No. 65,727'a Renewed- June 27, 1928.

armature operatively related to pole. piece structureof a magnet system, with readily accessible means manually operable toadjust the gap between the vibratile armature and pole piece structure without need foraccess to the adjusting screw or element itself.

Further in accordance with my invention, the adjusting screw or element is provided with a shoe or tip which engages thefpole v structure shown in Fig. 1.

piece structure and with respect to which the adjusting element or screw is rotatable.

My invention resides in structure and arrangement of parts of the character hereinf after described and claimed. A l

For an illustration of one of the various forms myinvention mayl take, reference is to be had to the accompanying drawings, in

which: j

Fig. 1 is a vertical sectional view, partly in elevation, -of a 'radio speaker embodying my invention.

Fig. 2 is aragmentary side elevation of the Fig. 3 is a rear elevational view of the magnet ysystem provided with air gap adjusting means.

Fig. 4 is a front elevational View of the structure shown in Fig. 3.

Fig. 5 is a horizontal sectional view," partly in plan, taken on the line 5 5 of Fig. 3.

Fig. 6 is a vertical sectional view, partly in elevation, taken on the line 6-6 of Fig. 3.'

Referring to the drawing, 1 is a base or support 'to which is secured by the screw 2 a bracket memberl 3 to which is secured byl therivet or equivalent member 4. one of the supportingv membcra and carrying jat their outer 'ends the gua-rd member 26,`which embraces and protects, but standsv free and j spaced from, the periphery of the diaphragm D, of paper o r other suitable material, coni-l Y cal in form and of relatively large diameter.v .As indicated, the magnet system may be of the characterfdisclosed in my prior application Serial No. 32,875 and in application Serial No. 41,031," tiled, repectively,'May. 26 and J uly'2, 1925.

The. substantially rectangular frame or yoke 6 of the magnet system is secured to the .supporting member 5a by screws Galextending through the spacing members 7 and having applied thereto 'ongthe rear .of the' support 5"11V the nuts 8.

Secured tothe frame or yoke 6 bythe same screws 6a are the inwardly extending pole pieces 9, in alignment with each other and between Whose inner ends is leftan air gap.

Surrounding the pole p ieces9are the windings or coils C traversed bytl1'e voiceor sound-representing current,such asexist's, for example, in the anode circuit of a detector yor audio frequency thermionie amplifier as com monly utilized in radio receiving apparatus.. The yoke 6 is preferably permanently magnetized, having lpoles of opposite signs at opposite ends thereof adjacent thepoints of y attachment-thereto of the polejpieces-9, 9,

whereby at the inner and adjacent ends of the' hollowor tubular shank 12 integral with the spacer member 13, to which one end of the armature l() issecured by the screw 14.

Integral with the yoke 6 is the bridging 6 on thatside thereof opposite to the armature 10. Threaded through the bridging member 15 is the adjusting element or screw 16, whose end adjacent the pole pieces 9 is recessed at 17 to receive the pivot pin 18 upon or integral with the shoe or ti 19, of

vpole pieces 9 are exhibited opposing north' I and south magnetic poles.

ole .pieces fmember 15, oii'set from the plane of the yoke A brass or other non-magnetic materia which has a flat face bridging the pole pieces 9 an engaging their rear faces.l L j 'The manually operable adjusting arm or lever 20 is threaded|- upon the screw 16, the lock nut 21, threaded upon screw 16, serving to lock the adjusting arm 20 in predetermined .angular position upon the screw 16 in fixed relation thereto, whereby manual rotation of the arm 2O about the. axis of the screw 16 rotates thelatter, causing its advance or reces toward or vaway from the armature 10, the tipA or shoe 19 remaining substantially fixed. with respect to the pole pieces, but partaking of. adjustment longitudinally of the axis of the screw 16 upon I otation of the latter with respect tothe shoe 19. Adjacent the screw 16 and nut 21, and the inner end of the adjusting lever 20, the aforementioned support .5EL Ais recessed or cupped,`as indicated at 5b.

i IIhe arm or lever 20 extends outwardly preferably to a distance greater than the diameter of the sup orting hub or member 5 and at its outer end has the ofset end or handle 20a grasped by the operator in effecting the adj. stment of air gap between 'armature and pole pieces.

By the structure described, the adjustment of gap between'the armature and `p ole pieces is possible at any time and quickly, even while the apparatus is in operation, Without need for access directly to the adjusting screw 16, whereby the sensitiveness of the telephone magnet system or the amplitude of vibration of the diaphragm may be adjusted quickly `without interruption of operation, to suit the varying orders of magnitude of sound-representing current of the receiving apparatus which may vary between wide limits for f several reasons, such, for example, as variation'of distances over which the -radio reception'is effected. v

The mode of attachment of the adjusting arm 20 to the screw'l is such as to provide adjustment of the arm withl respect te the adjusting screw, which latter is adjusted .to the usual or. normal position-at the factory and the arm 20 locked-in suchposition upon and to the screw -16 that the ultimate user may then effect adjustment of sensitiveness and amplitude between wide limits without changing thefadjustment of the arm 20 upon the screw16, though this ma be effected by loosening the lock'nut 21, Aetermining the new adjustment of the armr20 with respect to the screw 16, and-thereafter tightening thenut21. l 4

Threaded into the vibratile armature 10 is thepin 22, to which isv secured by set screw 1023 the sleeve. 24,to which are secured the 50' conical sheet metal members 25,-to which is secured the diaphragm D, whoseA periphery is embraced by and spaced from the guard 26. What I `claim is:

1. r1 he combination with a telephone magnet system comprising pole pieces spaced from each other and fromA a vibratile armature member, o f means for li'ecting adjustment of the air rap between said armature member and said pole pieces comprising a au j net system 'comprising' po e .pieces spaced slicey bridging said pole pleces and engaging.y

from each other and exhibitingA at their adjacent ends opposite magnetic polarities, and a co-acting armature member, of meansfor edecting adjustment of the air gap between said armature member and said pole pieces comprising a shoe of non-magnetic material bridging said pole pieces and engaging them frictionally to prevent rotation of said shoe, and an adjusting member engaging and movable with respect to said shoe.

3. The combination with a telephone magnet system comprising pole pieces spaced from each other and from a vibratile armature member, of means for effecting adjustment ofy the air gap between said armature member and said pole pieces comprisin rotatable axially movable adjusting mm er,

and a relatively ixed shoe engaged by .said adjusting member bridging said pole pleces and engaging them frictlonally to prevent roprevent rotation of said shoe member and engaged by said adjustingmember, one of said last named members having a recess and the other having a'pivotal extension disposed .in said recess.

5'. An amplifying telephone comprising a support having a depressed cen'tral portion,

-a telephone magnet system carried by said support, a diaphragm betweenwhich and said support said magnet system 1s disposed, a rotatable adjustin member for adjusting the `air gap of said magnet system, and f a manually operable arm secured to said adjusting member and disposed in said ldepressed portion. v g

6. An amplifying telephone comprising a support having a recess a telephone magnet systemfixedly mounted on said support, a

diaphragm between which and said support said vmagnet system is disposed, a rotatable adjusting member carried by said magnet.

system and disposed adjacent `said recess, f

and a manually operable arm-secured to said adjusting member adjacent said recess and extending radially therefrom.

7. An amplifying telephone comprising a support having a recess, a te ephone magnet.

system fxedly mounted on said support, a j

diaphragm between which. and'said supportsaid magnet system is disposed, a rotatable adjusting member carried by said. magnet f system and disposedadjacent said recess, and

a manually operable/arm` securedto said ad,

justing :memberl adjacent said-recess and disposed between sald support and said magnet system and extending radially `from said `afl-- justing member.

8. An'rampliying telephone .comprisinla support, a telephone magnet system ixe y mounted on said support, a'di-aphragm be` tween which and said support said. magnet Nsystem is disposed, a rotata le adjusting member `for adjusting the air gap of said magnet system, and a manually operable arm secured to said adjusting member and extending radially therefrom to a position for access from the opposite side of said support.

9. A n amplifying ltelephone comprising a support, a telephone magnet system carried by said support and comprising a vibratile armature and pole pieces, a conical diaphragm of large diameter vibrated by said armature, a rotatable adjusting member forv adjusting the air gap between said pole pieces and armature, and an adjusting arm secured to said adjusting memberI and disposed within the;

' l conical diaphragm.:

10. An amplifying Atelephonecomprising a support, a telephone magnet system carried` by said support and comprising a vibratile armature and pole pieces, a conical diaphragm of large diameter vibrated by said armature,

a1' rotatable adjusting member for adjusting' the air,y gap between said pole pieces mature, and an adjusting arm secured to said adjusting member and disposed Within the conical diaphragm between said' support. and

magnet system.

11. An amplifying telephone comprising a support, a telephone magnet system carried v by said support and comprising a vibratile armature and pole pieces, a conical diaphragm of large diameter carried by said armature, said magnet system disposed between said supportA and said diaphragm, a rotatable adjusting member for adjusting the air gap between said pole pieces and armature, and a manually operable arm secured to said adjusting member between said sup ort and said magnet system and disposed wit in said diaragm. 12. An amplifying telephone comprising a support, a telephone magnet system carrled by said support and comprising al vibratile armature and pole pieces, a conical diaphragm of large diameter vibrated by said armature, a rotatable adjusting member for 'adjusting the air gap between said pole'pieces and armature, and a manually operable member secured to said adjusting member and disposed within the conical diaphragm.

ARTHUR ATWATER.- KENT. f 

